class_docstr: Extension of QMatrix4x4 with some helpful methods added.
code: def matrix(self, nd=3):
      if nd == 3:
          return np.array(self.copyDataTo()).reshape(4, 4)
      elif nd == 2:
          m = np.array(self.copyDataTo()).reshape(4, 4)
          m[2] = m[3]
          m[:, 2] = m[:, 3]
          return m[:3, :3]
      else:
          raise Exception("Argument 'nd' must be 2 or 3")
  
file_path: pyqtgraph/pyqtgraph/Transform3D.py
imports: import numpy
  from .None import functions
  from .Qt import QtGui
  from .Vector import Vector
label_desc: Use image node_id 2 for calling the Transform3D obj's underlying member method code with example usage: obj.matrix(nd) and returns: np, m